1. Field of the Invention
The present invention relates to a pavement structure (hereinafter referred to merely as pavement) having good wear resistance, and more particularly to such pavement comprising a skeleton concrete formed by evenly spreading a mixture of aggregate, cement and water, the skeleton concrete including proper voids which are filled with a fluid material.
2. Description of the Prior Art
Conventionally, bituminous mixture, cement concrete or resin concrete is used for pavement. Bituminous pavement is advantageous in readiness of application and the most wide-spread pavement at present. However, the bituminous pavement is disadvantageous in that under a hot weather condition as in summer, plastic flow will be caused by repeated wheel load and the flatness of the pavement will be impaired, while in winter, it is quite readily subject to wear by studded tires and tire chains employed when driving on a snowy or icy road.
Cement concrete pavement causes no such plastic flow under a hot weather condition in summer, but it requires many days to be cured for construction and thence, traffic must be suspended during the curing period. In addition, as with the bituminous pavement, the cement concrete pavement suffers from wear by studded tires and tire chains employed in winter. Though the wear loss is slightly smaller than that of the bituminous pavement, it must be repaired, such as, by a process of overlaying a thin layer of a cement concrete material. The process requires drastically large cost and labor in comparison with bituminous pavement, and furthermore, the thickness of the layer is inevitably limited by the maximum size of aggregate.
In resin concrete pavement, wear loss is small in comparison with the above two types of pavement, nevertheless remaining to be a serious problem. In addition, because of limitation in handling time of the resin in use, special equipment is required for mixing and applying operation. Thus, the resin concrete pavement is not widely used at present, and it is sometimes used only for partial repair.
In recent years, block pavement using polymer-impregnated concrete blocks is applied for improved wear resistance. However, it requires manufacturing of such blocks including the steps of formation, deairing, and impregnation and polymerization of polymer in the factory, and setting the blocks one by one at the job site. Thus, it is disadvantageous in that it requires much cost and labor for construction. When the block pavement is used to repair a pavement, the existing road surface must be smoothly graded such as by deeply scraping the road surface, which further increases labor and cost for construction.
As described above, the serious problem of wear caused by studded tires and tire chains involved in the conventional paving technique has not been overcome by any of the above described types of pavement which cannot provide satisfactory performance and workability.